Question

multiple choice question
which neurotransmitter is released by all preganglionic and postganglionic parasympathetic neuron fibers?

norepinephrine (ne)
glutamate
acetylcholine (ach)
dopamine (da)

Explanation:

• Norepinephrine (NE): Released by most postganglionic sympathetic fibers, not parasympathetic.
• Glutamate: Main excitatory neurotransmitter in the central nervous system, not specific to parasympathetic neuron fibers.
• Acetylcholine (ACh): Released by all preganglionic neurons (both sympathetic and parasympathetic) and postganglionic parasympathetic neurons.
• Dopamine (DA): Involved in reward, motivation, etc., not related to this parasympathetic neuron fiber neurotransmitter role.

Answer:

acetylcholine (ACh)